[pct-l] FF and temperature ratings

[howie@jschool.troyst.edu (Hungry Howie)]

There is no industry standard for temperature ratings.  All ratings are
highly subjective.  I could be fine in a 30*F bag at 15*F, whereas you
might be cold at 40*F in the same bag.  Much of it has to do with an
individuals metabolic rate.  Other factors include weather conditions:
humidity, etc.  In a tarp with three sides touching the ground, and facing
away from the wind, I've been comfortable in my 30*F Marmot bag down to
17*F.  With the same tarp set up in high-humidity situations in an A-frame
style, I've been cold in the same bag at 45*F. That's a huge difference.
There are too many variables for there ever to be an industry standard.
The only way to compare bags is to measure loft.  Be sure to measure both
the overall loft and the top/bottom loft.  Many companies put about 60% of
insulation on the top, seeing as that's where you gain 85% of your warmth.

Howie